Bacterial cells utilize both two-component signaling proteins and alternative sigma (?) factors to modulate transcription in response to environmental stress. These environmental stress regulatory proteins are known to function as essential virulence factors in numerous bacterial pathogens. Bacterial stress responses play a fundamental role in bacterial growth, biofilm formation, pathogenesis and symbiosis. My proposed structural studies on the Caulobacter crescentus general stress signaling pathway, which integrates feature of two-component signaling and alternative s regulation, will significantly enhance our understanding of the molecular and structural basis of stress adaptation in the alphaproteobacteria. The Crosson lab has a successful track record utilizing techniques from a wide range of disciplines to pursue questions focused on molecular microbial physiology. Their broad interdisciplinary approaches promise to provide a more complete understanding of how bacterial cells can perceive and adapt to changes within their environment. My postdoctoral training in the Crosson Lab, focused on molecular biophysics and structural biology of the PhyR, ?T and NepR proteins, will facilitate my successful transition into an independent faculty position, where my research will center on molecular aspects of microbial signaling.